Valve actuation inlet noise control system

Abstract

An engine noise control system ( 100 ) controls engine noise in multiple engine operating modes by controlling a size of an air inlet ( 104 ) with a movable valve. An actuator ( 114 ) moves the valve ( 112 ) between an open position and a closed position depending on the engine operating mode, to control the amount of air travelling into an air cleaner. The actuator ( 114 ) is coupled to an engine cylinder de-activation unit ( 200 ) to link the valve operation to the engine operating mode. When the engine is operating in a low-power mode, which requires less air, the actuator ( 114 ) moves a cable drive ( 204 ), which rotates an actuation lever ( 208 ) that turns the valve ( 112 ) into a closed position. When the engine is operating in a high-power mode, the actuator ( 114 ) moves the cable drive ( 204 ) to move the valve ( 112 ) to an open position. Reducing the effective cross sectional area of the air inlet increases a ratio between the air cleaner ( 102 ) area and the duct area, increasing the attenuation characteristics of the system.

What is claimed is:  
     
         1 . A noise control system for an engine having an air inlet and that operates in a first mode and a second mode, comprising: 
 a valve disposed in the air inlet;    an actuating mechanism operably coupled to the valve to move the valve between an open position and a closed position; and    a controller that switches the engine between the first and second mode and controls the actuating mechanism to move the valve to the open position during the first mode and to the closed position during the second mode.    
     
     
         2 . The noise control system of  claim 1 , wherein the valve is disposed in the air inlet to allow air to flow through approximately half of the air inlet when the valve is in the closed position.  
     
     
         3 . The noise control system of  claim 1 , wherein the actuator system comprises: 
 a cable having a movable end and a fixed end; and    an actuator connected to the movable end and to the controller, wherein the actuator applies a force to the cable when the controller switches to one of the first mode and the second mode.    
     
     
         4 . The noise control system of  claim 3 , further comprising: 
 an actuation lever connected to the fixed end of the cable; and    a valve actuation shaft connected to the actuator lever and the valve, wherein movement of the actuation lever rotates the valve actuation shaft to move the valve between the open position and the closed position.    
     
     
         5 . The noise control system of  claim 4 , further comprising a resilient member that applies a biasing force to the actuation lever.  
     
     
         6 . The noise control system of  claim 5 , wherein the biasing force of the resilient member is in a direction opposite one direction of motion of the actuation lever when the actuation lever is actuated.  
     
     
         7 . The noise control system of  claim 3 , wherein the cable is one selected from the group consisting of a Bowden cable and a sleeved flexible cable that can transmit at least one of a compressive load and a tensile load.  
     
     
         8 . A noise control system for an engine having an air inlet and that operates in a high-power mode and a low-power mode, comprising: 
 a valve disposed in the air inlet, wherein the valve is disposed in the air inlet to allow air to flow through approximately half of the air inlet when the valve is in the closed position;    a cable having a movable end and a fixed end, wherein the cable transmits at least one of a tensile load and a compressive load;    a cylinder de-activation unit that switches the engine between the high-power mode and the low-power mode; and    an actuator connected to the movable end and operably coupled to the cylinder deactivation unit, wherein the actuator applies a first force to the cable when the cylinder deactivation unit switches to the high-power mode to open the valve and applies a second force to the cable when the cylinder de-activation unit switches to the low-power mode to close the valve.    
     
     
         9 . The noise control system of  claim 8 , further comprising: 
 an actuation lever connected to the fixed end of the cable;    a valve actuation shaft connected to the actuator lever and the valve, wherein movement of the actuation lever rotates the valve actuation shaft to move the valve between the open position and the closed position.    
     
     
         10 . The noise control system of  claim 9 , further comprising a resilient member that applies a biasing force to the actuation lever.  
     
     
         11 . The noise control system of  claim 10 , wherein the biasing force of the resilient member is in a direction opposite one direction of motion of the actuation lever when the actuation lever is actuated.